Pure Cartilage-Based Repair Modalities of Focal Cartilage Lesions

Abstract

Focal cartilage lesions in diarthrodial joints have a limited capacity to heal, and repair techniques used at present are still unable to provide a universal solution. Osteochondral auto- and allografts are accepted and successful methods for the treatment of these lesions, but occasionally the osseal incorporation is delayed or insufficient and graft integration might be unsuccessful. Failure at this level generates a large osseos crater and the consequences can prove challenging.

Until just a few years ago, it was a generally accepted dogma that when cartilage is detached from the subchondral bone it would fail to reintegrate to its bed and its surrounding cartilage. Recently, innovative approaches have been established to repair cartilage defects using pure cartilage-based implants, and so far they seem to have had considerable success.

One of the available options is to use autologous minced cartilage in a single-stage procedure. Cartilage tissue is obtained from the less-weight-bearing surface of the affected joint and the sample is processed in situ resulting in a cartilage fragment-loaded scaffold that can be applied to the lesion of the weight-bearing area. Another system repairs with cadaveric juvenile articular hyaline cartilage cut into 1 mm3-cartilage cubes and using fibrin glue as vehicle the tissue particles are evenly distributed on the defected articular surface. Both methods are relatively new and therefore lacking long-term follow up, but the short-term results seem encouraging.

An additional concept for cartilage-based repair is when pure cartilage allograft is peeled from the subchondral bone, and instead of mincing the tissue it is repeatedly incised on its basilar surface rendering the rigid cartilage graft into a rather pliable graft. Since the superficial layer is preserved the graft is similar to any scaffold used in cartilage repair, and it can be secured to the lesion site using sutures and fibrin glue. Although this method is in the experimental phase, a short term clinical trial has proved it to be safe.

In this chapter we will briefly describe the physiology of cartilage integration; summarize the basis and the potential pitfalls of these methods; and provide a review of the available data on the clinical outcomes.